Potassium sulfate is a standard laboratory agent used in a variety of research applications. It is used to determine nitrogen and protein in food in the Kjeldahl method. It has been used to research electrostatic effects on pKa values of amino acid residues in the staphylococcal nuclease. When a buffer with a high zwitterionic salt concentration is used, Potassium sulfate can be used to improve protein separation via capillary zone electrophoresis. It has been reported to be useful to adsorb immune complexes on agarose derivative adsorbents.